Internal combustion engines using a vaporized admixture of air and gasoline or some other like combustible substance are invariably provided with an air intake system. An attendant problem with the use of such engines is the hazard of engine backfire. If the engine backfires through the carburetor in a volatile environment there is a substantial risk of injury to person and property unless the air intake system is provided with means to arrest or retard the flame emerging from the carburetor.
The prior art has included various approaches to the solution of this problem; most of which have required extensive and costly changes to the design of the conventional air intake system and its filter element.
One approach has been to provide the overhead portion of the air intake assembly with an interior, downwardly projecting dome adapted to reflect a flame emerging from the carburetor away from the filter element. Besides requiring a costly reworking of the air intake assembly, this system has no positive feature to arrest or attenuate the spreading flame.
Another approach has been to immerse the porous material in the filtering element in water soluble oil saturates or other like flame retardant solutions. The cost and manufacturing disadvantages of this solution are manifest.
Thus it has become desireable to design a relatively low-cost, readily manufacturable device that will provide positive flame arresting or retarding means in the event of engine backfire through the carburetor without otherwise detracting from the efficient operation of the air intake system. Such is the objective of the present invention.